In U.S. Pat. No. 6,495,014, the entire disclosure of which is incorporated by reference, there was described an ion-exchange resin wafer designed for use in an electrodeionization (EDI) process. The ion-exchange resin wafer disclosed in the '014 patent overcame internal fluid leakage problems. The resin wafer technology enabled the application of EDI technology to desalination of chemical products. The '014 patent described a detailed method to fabricate wafers using latex binders through a polymerization process. U.S. patent application publication nos. 2004/0060875, now U.S. Pat. No. 6,797,140 issued Sep. 28, 2004 and 2004/0115783, the disclosures of which are herein incorporated by reference, relate to latex wafers and devices incorporating same. The new resin wafers disclosed herein greatly increase the performance of devices in a variety of applications, as well as new devices and uses.
The wafers using latex binders described in the '014 patent were adequate for their intended purpose but there were problems in the length of time it took to make those wafers due to the setting times for the latex binding material as well as the separation and capture efficiencies in enzymatic bioreactors using these wafers.
Accordingly, there is a need in this art for material which will increase the separation and capture efficiency for enzymatic bioreactors as well as new methods for manufacturing wafers to accommodate commercial production requirements.
In investigating ways to improve wafers of the type described in the '014 patent, it was found that new wafers could be made with improved characteristics more quickly and efficiently than previously by the use of thermoplastic binders such as polyethylene rather than latex and when combined with an electrically conducting material, provided not only improved characteristics with respect to the prior art wafers made with latex binders but also enabled the wafers to be used in new devices.